Drive-in and Drive-through pallet racking are storage rack configurations that allow the forklift to drive directly into the lane of stacked rows (called a bay). The difference between a drive-in and a drive-thru pallet racking system is simply whether the bays have an entry at only one end, or at both ends. Drive-in pallet racks use a common entry and exit, while drive-through pallet racks have entry points at either end of the bay. Because a drive-in pallet racking system has only one entrance, it uses what is called a LIFO (last in, first out) storage method. With only one entrance, the last pallet put into a row is necessarily the first one to be taken out.
   A drive-through storage system, with two different entry points, can also use a FIFO (first in, first out) storage method. With a FIFO system, pallets are loaded in one end and are pushed back to the other end, where they are then at the front of the row on the opposite side. The first pallet put into such a row is the first one taken out at the other end. This system is advantageous for material with an expiration date or wherever shelf life is a major concern

   Many types of pallet racks are available with different designs to fulfill specific functions or create specific advantages. When deciding on the type of a pallet racking systems to use, several basic considerations have to be taken into account:
* Desired storage density
* Floor space and building height
* Placement of building doors and columns
* Inventory accessibility
* Inventory rotation
* Item/load size and weight
* Optimal storage design
* Cost of materials and installation